1. Field of the Invention
The present invention relates generally to a hydraulic control module and, more specifically, to a control valve for use in a hydraulic control module.
2. Description of the Related Art
Conventional vehicle powertrain systems known in the art typically include an engine in rotational communication with a transmission. The engine generates rotational torque which is selectively translated to the transmission which, in turn, translates rotational torque to one or more wheels. Typical transmissions are shifted in discrete steps between a high-torque, low-speed mode for starting a vehicle and a high-speed, low-torque mode for vehicle operation at highway speeds. In a manual transmission, shifting is accomplished by the manual controlled engagement of gear sets. In an automatic transmission, shifting is accomplished by the automatic controlled engagement of friction elements.
To facilitate shifting and controlled engagement of the friction elements of the automatic transmission, the hydraulic control assembly typically includes a pump to provide pressurized hydraulic fluid, and a plurality of control valves for controlling the flow of hydraulic fluid through the hydraulic circuit.
Conventional control valves used to control the flow of hydraulic fluid through the hydraulic circuit include a metal insert defining a fluid passage, a valve member slidably disposed in the fluid passage for controlling the flow of hydraulic fluid, and a composite valve body disposed around the metal insert.
Composite valve bodies of conventional control valves have a first and second protrusion disposed about an axis, with the first protrusion being spaced from the second protrusion along the axis. In conventional control valves, the composite valve body defines a plurality of fluid ports about the axis between the first and second protrusion, and the metal insert defines a plurality of fluid ports about the axis, with the plurality of fluid ports defined by the composite valve body and the plurality of fluid ports defined by the metal insert allowing the flow of hydraulic fluid therethrough between the first and second protrusions to enter into the fluid passage.
To provide sufficient support and strength for the composite valve body, the composite valve body in conventional control valves includes composite material between the first and second protrusions about the axis and between each of the fluid ports defined by the composite valve body. Having this composite material between the first and second protrusions about the axis and between each of the fluid ports provides ensures sufficient support and strength for the composite valve body, especially in high pressure applications. However, this composite material between the first and second protrusions about the axis and between each of the fluid ports of conventional composite valve bodies tends to obstruct the flow of hydraulic fluid between the first and second protrusions. Specifically, the presence of excess composite material reduces a flow area defined by the plurality of fluid ports between the first and second protrusions, which decreases the amount of hydraulic fluid that flows into and out of the fluid passage of the metal insert.
In recent years, there has been a need to improve the flow of the hydraulic fluid through control valves, to decrease weight of control valves, to decrease manufacturing and packaging costs of control valves, and to decrease manufacturing time of control valves.
As such, there remains a need to provide an improved control valve that has improved flow of hydraulic fluid, is decreased in weight, that decreases manufacturing and packaging costs, and that decreases manufacturing time. Additionally, there remains a need to provide for a method of making the control valve.